The invention relates to a closure sequence control arrangement for turnable double doors.
In order to lock double doors to each other one door leaf, a so called active door, is provided preferably with a latch bolt protruding from a lock case mounted in the active door. As a consequence the door leaves must be closed in a certain order so that the active door provided with the latch bolt is closed last. Thereby the spring loaded latch bolt can be pressed, due to its bevelled guiding surface, into the lock case in order to fully close the active door. In the closed position, the latch bolt can move again, urged by the spring, into its protruding position in which it engages the passive or auxiliary door and locks the door leaves to each other.
A closure sequence control arrangement is disclosed in the document EP 0 458 034. In this known arrangement a clamping plate is utilized which is turnable around a certain journal point and through an opening of which a sliding bar, dependent on the movements of the active door, extends. In case the auxiliary door is too far open, the clamping plate is able to turn, whereby the sliding bar is tightly clamped against the edges of the opening and thus its movement is prevented. Keeping the clamping plate in its neutral position, which allows movement of the sliding bar, requires on the one hand spring load and on the other hand a sliding bar connected to the movements of the auxiliary door. This sliding bar is utilized also to release the locking provided by the clamping plate. The arrangement is complicated both as to its construction and its operation.
A closure sequence control arrangement with considerably simpler construction is disclosed in the document EP 0 867 587. This arrangement makes use of a blocking piece moving transversely in a guide rail and which, on the basis of the position of a connection arm dependent on the movements of the auxiliary door, prevents or allows movement in the direction of the guide rail of the head of a turning arm attached to the active door. This arrangement cannot, however, be utilized for instance for selective hold-opening of the active door at different opening angles.
A further closure sequence control arrangement is disclosed in the document DE 195 45 401 A1, according to which the sequence control unit includes a wedge-like member which is arranged to press a sliding bar against the inner surface of a guide rail, which for this purpose is provided with a friction coating at the position of the sequence control unit. Additionally the operation of the wedge-like member makes use of bearing means to provide for movement thereof.
An aim of the invention is to provide a new and improved closure sequence control arrangement for double doors, from which the defects and drawbacks of the prior known arrangements are essentially eliminated. An aim of the invention is more clearly to provide a closure sequence control arrangement for double doors, which is simple as to its construction and is operationally reliable. A further aim is that the arrangement can easily be applied to provide hold-open function for the active door in different opening positions as selected.
In accordance with the invention the sequence control unit includes a lock body element, which has a chamber through which a first elongate sliding bar is led and within which a blocking member is located. The chamber is provided with a guiding surface, which is inclined with regard to the first sliding bar and acts on the blocking member for providing a clamping effect. Hereby the sliding bar is supported by the lock body element and the blocking member can be tightly pressed between the sliding bar and the guiding surface. The arrangement is simple since it does not require that the blocking member be turnably supported around any certain journal point. On the other hand since the blocking member is moved in the direction of the sliding bar, its blocking function is not dependent on the sliding bar being in any particular position and thus on the actual opening position of the active door, which enables hold-opening of the active door invariably in different hold-open positions according to need.
The guiding surface is with advantage a surface of a separate guiding member installed in the chamber. In this case it can with advantage be of some hard and wear resistant material, for instance hardened steel, independent of the material of the lock body element itself.
The chamber encloses with advantage a bias spring means arranged to urge the blocking member in the direction for providing the clamping effect. Hereby it can be ensured that the blocking member can grip the sliding bar for providing the clamping effect so that the sliding bar is locked and remains immovably in its position.
A so-called overload protection can with advantage be provided so that the lock body element is movably supported to a body member of the sequence control unit fixed to the guide rail. Then the movement of the lock body element in the direction for providing the clamping effect can be arranged to occur against the force of a spring. The spring may be supported to the body member and installed on an adjustment screw which extends through the wall of the body member and is in threaded engagement with the lock body element.
By locating the lock body element and the body member in the guide rail horizontally beside the first sliding bar it is possible to provide a construction that has a small vertical height and, thus, requires little space.
The sliding bar functionally connected to the second door leaf is movably supported to the body member and is arranged to act on the blocking member for opening the clamped-in condition of the first sliding bar at the end phase of the closing of the second door leaf. In practice the head of the second sliding bar is arranged to press the blocking member against the force of the bias spring means for releasing the clamped-in condition. Hereby releasing of the locking provided by the blocking member is carried out simply and reliably.
The first sliding bar may with advantage be provided with transversal grooves, recesses or the like which are arranged in cooperation with the blocking member so that they enhance the force exerted by the blocking member on the sliding bar and at the same time keeping the first door leaf open.
An advantageous arrangement in view of construction, operation and manufacturing technique can be accomplished in case the blocking member is a roller or a corresponding cylinder-shaped member.